They're called "energy drinks" and they have names like Red Bull and Adrenaline Rush. They're practically packed in the lunch boxes of American children and you can buy them in bars, clubs and even Wal-Mart.But critics worry the drinks can cause problems for athletes and for people who mix them with alcohol.
Energy drinks contain vitamins, large amounts of sugar, amino acids and about the same amount of caffeine as a cup of coffee. But the formula still poses problems for some. "They're sugar and caffeine," says one sports nutritionist. "And that's not good."
The Red Bull Web site says the amino acid it contains, taurine, "acts as a metabolic transmitter and additionally has a detoxifying effect and strengthens cardiac contractility." But these are disputed by scientists.